diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/EternalCoreApiProvider.java b/eternalcore-api/src/main/java/com/eternalcode/core/EternalCoreApiProvider.java
index ebddebaef..4f991f9da 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/EternalCoreApiProvider.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/EternalCoreApiProvider.java
@@ -1,7 +1,11 @@
 package com.eternalcode.core;
 
+import org.jetbrains.annotations.ApiStatus;
+import org.jspecify.annotations.Nullable;
+
 public final class EternalCoreApiProvider {
 
+    @Nullable
     private static EternalCoreApi api;
 
     private EternalCoreApiProvider() {
@@ -16,6 +20,7 @@ public static EternalCoreApi provide() {
         return api;
     }
 
+    @ApiStatus.Internal
     static void initialize(EternalCoreApi api) {
         if (EternalCoreApiProvider.api != null) {
             throw new IllegalStateException("EternalCoreApiProvider is already initialized");
@@ -28,6 +33,7 @@ static void initialize(EternalCoreApi api) {
         EternalCoreApiProvider.api = api;
     }
 
+    @ApiStatus.Internal
     static void deinitialize() {
         if (EternalCoreApiProvider.api == null) {
             throw new IllegalStateException("EternalCoreApiProvider is not initialized");
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/adminchat/AdminChatService.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/adminchat/AdminChatService.java
index 7df72cbfe..c834cfc0b 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/adminchat/AdminChatService.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/adminchat/AdminChatService.java
@@ -39,7 +39,6 @@ public interface AdminChatService {
      *
      * @return an unmodifiable collection of player UUIDs with enabled admin chat
      */
-    @NonNull
     @Unmodifiable
     Collection<UUID> getPlayersWithEnabledChat();
 
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/adminchat/event/AdminChatEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/adminchat/event/AdminChatEvent.java
index 2b4aefbc6..5c97e65cb 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/adminchat/event/AdminChatEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/adminchat/event/AdminChatEvent.java
@@ -1,5 +1,6 @@
 package com.eternalcode.core.feature.adminchat.event;
 
+import java.util.Objects;
 import org.bukkit.command.CommandSender;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.Event;
@@ -21,40 +22,27 @@ public class AdminChatEvent extends Event implements Cancellable {
     private String content;
     private boolean cancelled;
 
-    public AdminChatEvent(@NonNull CommandSender sender, @NonNull String content) {
+    public AdminChatEvent(CommandSender sender, String content) {
         super(false);
 
-        if (sender == null) {
-            throw new IllegalArgumentException("Sender cannot be null");
-        }
-        if (content == null) {
-            throw new IllegalArgumentException("Content cannot be null");
-        }
-
-        this.sender = sender;
-        this.content = content;
+        this.sender = Objects.requireNonNull(sender, "sender cannot be null");
+        this.content = Objects.requireNonNull(content, "content cannot be null");
         this.cancelled = false;
     }
 
-    @NonNull
     public static HandlerList getHandlerList() {
         return HANDLER_LIST;
     }
 
-    @NonNull
     public CommandSender getSender() {
         return this.sender;
     }
 
-    @NonNull
     public String getContent() {
         return this.content;
     }
 
-    public void setContent(@NonNull String content) {
-        if (content == null) {
-            throw new IllegalArgumentException("Content cannot be null");
-        }
+    public void setContent(String content) {
         this.content = content;
     }
 
@@ -69,8 +57,7 @@ public void setCancelled(boolean cancelled) {
     }
 
     @Override
-    @NonNull
-    public HandlerList getHandlers() {
+    public @NonNull HandlerList getHandlers() {
         return HANDLER_LIST;
     }
 }
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/butcher/ButcherEntityRemoveEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/butcher/ButcherEntityRemoveEvent.java
index 7fb661f75..290e18888 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/butcher/ButcherEntityRemoveEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/butcher/ButcherEntityRemoveEvent.java
@@ -4,6 +4,7 @@
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
+import org.jspecify.annotations.NonNull;
 
 public class ButcherEntityRemoveEvent extends Event implements Cancellable {
 
@@ -31,7 +32,7 @@ public Entity getEntity() {
     }
 
     @Override
-    public HandlerList getHandlers() {
+    public @NonNull HandlerList getHandlers() {
         return HANDLER_LIST;
     }
 
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/catboy/event/CatboySwitchEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/catboy/event/CatboySwitchEvent.java
index cc3fa0804..febcee7bf 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/catboy/event/CatboySwitchEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/catboy/event/CatboySwitchEvent.java
@@ -3,6 +3,7 @@
 import org.bukkit.entity.Player;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerEvent;
+import org.jspecify.annotations.NonNull;
 
 /**
  * Called when a player switches their catboy status.
@@ -26,7 +27,7 @@ public boolean isCatboy() {
     }
 
     @Override
-    public HandlerList getHandlers() {
+    public @NonNull HandlerList getHandlers() {
         return HANDLER_LIST;
     }
 
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/chat/event/ClearChatEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/chat/event/ClearChatEvent.java
index 2f5fd8a46..8d9ed8ae9 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/chat/event/ClearChatEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/chat/event/ClearChatEvent.java
@@ -4,6 +4,7 @@
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
+import org.jspecify.annotations.NonNull;
 
 /**
  * Called when one of the server administrators clear chat using /chat clear command.
@@ -35,7 +36,7 @@ public void setCancelled(boolean cancelled) {
     }
 
     @Override
-    public HandlerList getHandlers() {
+    public @NonNull HandlerList getHandlers() {
         return HANDLER_LIST;
     }
 
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/chat/event/DisableChatEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/chat/event/DisableChatEvent.java
index 388b9be97..0963423b1 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/chat/event/DisableChatEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/chat/event/DisableChatEvent.java
@@ -4,6 +4,7 @@
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
+import org.jspecify.annotations.NonNull;
 
 /**
  * Called when one of the server administrators disables chat using /chat off command.
@@ -35,7 +36,7 @@ public void setCancelled(boolean cancelled) {
     }
 
     @Override
-    public HandlerList getHandlers() {
+    public @NonNull HandlerList getHandlers() {
         return HANDLER_LIST;
     }
 
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/chat/event/EditSlowModeEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/chat/event/EditSlowModeEvent.java
index 7fc9f3ab4..234f1fd3d 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/chat/event/EditSlowModeEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/chat/event/EditSlowModeEvent.java
@@ -6,6 +6,7 @@
 
 import java.time.Duration;
 import java.util.UUID;
+import org.jspecify.annotations.NonNull;
 
 /**
  * Called when one of the server administrators edit slowmode chat using /chat slowmode command.
@@ -54,7 +55,7 @@ public void setCancelled(boolean cancelled) {
     }
 
     @Override
-    public HandlerList getHandlers() {
+    public @NonNull HandlerList getHandlers() {
         return HANDLER_LIST;
     }
 
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/chat/event/EnableChatEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/chat/event/EnableChatEvent.java
index b1ca96d00..cff4796ed 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/chat/event/EnableChatEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/chat/event/EnableChatEvent.java
@@ -4,6 +4,7 @@
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
+import org.jspecify.annotations.NonNull;
 
 /**
  * Called when one of the server administrators enables chat using /chat on command.
@@ -35,7 +36,7 @@ public void setCancelled(boolean cancelled) {
     }
 
     @Override
-    public HandlerList getHandlers() {
+    public @NonNull HandlerList getHandlers() {
         return HANDLER_LIST;
     }
 
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/helpop/event/HelpOpEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/helpop/event/HelpOpEvent.java
index 76490a02e..265b678a9 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/helpop/event/HelpOpEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/helpop/event/HelpOpEvent.java
@@ -4,6 +4,7 @@
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
+import org.jspecify.annotations.NonNull;
 
 public class HelpOpEvent extends Event implements Cancellable {
 
@@ -39,7 +40,7 @@ public void setCancelled(boolean cancel) {
     }
 
     @Override
-    public HandlerList getHandlers() {
+    public @NonNull HandlerList getHandlers() {
         return HANDLER_LIST;
     }
 
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/HomeCreateEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/HomeCreateEvent.java
index b9d2e426f..87b669a54 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/HomeCreateEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/HomeCreateEvent.java
@@ -5,6 +5,7 @@
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
+import org.jspecify.annotations.NonNull;
 
 /**
  * Event called when a home is created.
@@ -62,7 +63,7 @@ public void setCancelled(boolean cancel) {
     }
 
     @Override
-    public HandlerList getHandlers() {
+    public @NonNull HandlerList getHandlers() {
         return HANDLER_LIST;
     }
 
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/HomeDeleteEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/HomeDeleteEvent.java
index 066f3349c..c86e9bccb 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/HomeDeleteEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/HomeDeleteEvent.java
@@ -6,6 +6,7 @@
 import org.bukkit.event.HandlerList;
 
 import java.util.UUID;
+import org.jspecify.annotations.NonNull;
 
 /**
  * Event called when a home is deleted.
@@ -44,7 +45,7 @@ public void setCancelled(boolean cancel) {
     }
 
     @Override
-    public HandlerList getHandlers() {
+    public @NonNull HandlerList getHandlers() {
         return HANDLER_LIST;
     }
 
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/HomeLimitReachedEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/HomeLimitReachedEvent.java
index 2bae366d1..38ff130f3 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/HomeLimitReachedEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/HomeLimitReachedEvent.java
@@ -4,6 +4,7 @@
 import org.bukkit.event.HandlerList;
 
 import java.util.UUID;
+import org.jspecify.annotations.NonNull;
 
 /**
  * Event called when a player tries to create a home but has reached the limit.
@@ -37,7 +38,7 @@ public int getLimitAmount() {
     }
 
     @Override
-    public HandlerList getHandlers() {
+    public @NonNull HandlerList getHandlers() {
         return HANDLER_LIST;
     }
 
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/HomeOverrideEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/HomeOverrideEvent.java
index 8fd427321..9903614d8 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/HomeOverrideEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/HomeOverrideEvent.java
@@ -1,11 +1,11 @@
 package com.eternalcode.core.feature.home.event;
 
-import com.eternalcode.core.feature.home.Home;
 import java.util.UUID;
 import org.bukkit.Location;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
+import org.jspecify.annotations.NonNull;
 
 /**
  * Event called when a home is overridden with new location.
@@ -64,7 +64,7 @@ public void setCancelled(boolean cancel) {
     }
 
     @Override
-    public HandlerList getHandlers() {
+    public @NonNull HandlerList getHandlers() {
         return HANDLER_LIST;
     }
 
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/HomeTeleportEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/HomeTeleportEvent.java
index 24dded3ba..8e60e0e29 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/HomeTeleportEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/HomeTeleportEvent.java
@@ -1,11 +1,11 @@
 package com.eternalcode.core.feature.home.event;
 
 import com.eternalcode.core.feature.home.Home;
-import org.bukkit.event.Cancellable;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
 
 import java.util.UUID;
+import org.jspecify.annotations.NonNull;
 
 /**
  * Called after teleportation to home.
@@ -37,7 +37,7 @@ public static HandlerList getHandlerList() {
     }
 
     @Override
-    public HandlerList getHandlers() {
+    public @NonNull HandlerList getHandlers() {
         return HANDLER_LIST;
     }
 }
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/PreHomeTeleportEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/PreHomeTeleportEvent.java
index b0ecc3d08..75dbffc34 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/PreHomeTeleportEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/home/event/PreHomeTeleportEvent.java
@@ -6,6 +6,7 @@
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
+import org.jspecify.annotations.NonNull;
 
 /**
  * Called before teleportation to home.
@@ -59,7 +60,7 @@ public static HandlerList getHandlerList() {
     }
 
     @Override
-    public HandlerList getHandlers() {
+    public @NonNull HandlerList getHandlers() {
         return HANDLER_LIST;
     }
 }
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/ignore/event/IgnoreAllEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/ignore/event/IgnoreAllEvent.java
index d4f479988..0255cbc96 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/ignore/event/IgnoreAllEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/ignore/event/IgnoreAllEvent.java
@@ -38,9 +38,8 @@ public void setCancelled(boolean cancel) {
         this.cancelled = cancel;
     }
 
-    @NonNull
     @Override
-    public HandlerList getHandlers() {
+    public @NonNull HandlerList getHandlers() {
         return HANDLER_LIST;
     }
 
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/ignore/event/UnIgnoreAllEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/ignore/event/UnIgnoreAllEvent.java
index 5ff664b22..01980adb8 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/ignore/event/UnIgnoreAllEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/ignore/event/UnIgnoreAllEvent.java
@@ -38,9 +38,8 @@ public void setCancelled(boolean cancel) {
         this.cancelled = cancel;
     }
 
-    @NonNull
     @Override
-    public HandlerList getHandlers() {
+    public @NonNull HandlerList getHandlers() {
         return HANDLER_LIST;
     }
 
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/ignore/event/UnIgnoreEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/ignore/event/UnIgnoreEvent.java
index 7a4343acf..3be14cf83 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/ignore/event/UnIgnoreEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/ignore/event/UnIgnoreEvent.java
@@ -47,9 +47,8 @@ public void setCancelled(boolean cancel) {
         this.cancelled = cancel;
     }
 
-    @NonNull
     @Override
-    public HandlerList getHandlers() {
+    public @NonNull HandlerList getHandlers() {
         return HANDLER_LIST;
     }
 
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/jail/event/JailDetainEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/jail/event/JailDetainEvent.java
index 012b2776e..a1331a39b 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/jail/event/JailDetainEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/jail/event/JailDetainEvent.java
@@ -5,6 +5,7 @@
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerEvent;
+import org.jspecify.annotations.NonNull;
 
 public class JailDetainEvent extends PlayerEvent implements Cancellable {
 
@@ -34,7 +35,7 @@ public void setCancelled(boolean cancel) {
     }
 
     @Override
-    public HandlerList getHandlers() {
+    public @NonNull HandlerList getHandlers() {
         return HANDLER_LIST;
     }
 
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/jail/event/JailReleaseEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/jail/event/JailReleaseEvent.java
index dd5e0d4ff..4d534421a 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/jail/event/JailReleaseEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/jail/event/JailReleaseEvent.java
@@ -5,6 +5,7 @@
 import org.bukkit.event.HandlerList;
 
 import java.util.UUID;
+import org.jspecify.annotations.NonNull;
 
 public class JailReleaseEvent extends Event implements Cancellable {
 
@@ -32,7 +33,7 @@ public void setCancelled(boolean cancel) {
     }
 
     @Override
-    public HandlerList getHandlers() {
+    public @NonNull HandlerList getHandlers() {
         return HANDLER_LIST;
     }
 
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/msg/MsgEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/msg/MsgEvent.java
index fb5c21304..8c35ca87e 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/msg/MsgEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/msg/MsgEvent.java
@@ -3,6 +3,7 @@
 import java.util.UUID;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
+import org.jspecify.annotations.NonNull;
 
 /**
  * Event that is called when a player sends a private message to another player.
@@ -40,7 +41,7 @@ public String getContent() {
     }
 
     @Override
-    public HandlerList getHandlers() {
+    public @NonNull HandlerList getHandlers() {
         return HANDLER_LIST;
     }
 
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/randomteleport/event/PreRandomTeleportEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/randomteleport/event/PreRandomTeleportEvent.java
index 2ab22a03c..d13c425b9 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/randomteleport/event/PreRandomTeleportEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/randomteleport/event/PreRandomTeleportEvent.java
@@ -4,6 +4,7 @@
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
+import org.jspecify.annotations.NonNull;
 
 /**
  * Called before a player is teleported to a random location.
@@ -36,7 +37,7 @@ public void setCancelled(boolean cancel) {
     }
 
     @Override
-    public HandlerList getHandlers() {
+    public @NonNull HandlerList getHandlers() {
         return HANDLER_LIST;
     }
 
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/randomteleport/event/RandomTeleportEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/randomteleport/event/RandomTeleportEvent.java
index 1a8eac255..1e8d681ad 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/randomteleport/event/RandomTeleportEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/randomteleport/event/RandomTeleportEvent.java
@@ -4,6 +4,7 @@
 import org.bukkit.entity.Player;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
+import org.jspecify.annotations.NonNull;
 
 /**
  * Called after a player is teleported to a random location.
@@ -31,7 +32,7 @@ public Location getTeleportLocation() {
     }
 
     @Override
-    public HandlerList getHandlers() {
+    public @NonNull HandlerList getHandlers() {
         return HANDLER_LIST;
     }
 
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/spawn/SpawnService.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/spawn/SpawnService.java
index d2680d2e4..9236bc0ef 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/spawn/SpawnService.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/spawn/SpawnService.java
@@ -2,6 +2,7 @@
 
 import org.bukkit.Location;
 import org.bukkit.entity.Player;
+import org.jspecify.annotations.Nullable;
 
 public interface SpawnService {
 
@@ -21,5 +22,5 @@ public interface SpawnService {
     /**
      * Provides the spawn location in the game.
      */
-    Location getSpawnLocation();
+    @Nullable Location getSpawnLocation();
 }
\ No newline at end of file
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/vanish/VanishService.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/vanish/VanishService.java
index bc9cebc17..a868b6d81 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/vanish/VanishService.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/vanish/VanishService.java
@@ -1,10 +1,9 @@
 package com.eternalcode.core.feature.vanish;
 
-import org.bukkit.entity.Player;
-import org.jetbrains.annotations.ApiStatus;
-
 import java.util.Set;
 import java.util.UUID;
+import org.bukkit.entity.Player;
+import org.jetbrains.annotations.ApiStatus;
 
 public interface VanishService {
 
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/warp/event/PreWarpTeleportEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/warp/event/PreWarpTeleportEvent.java
index cdb6a6c10..1b28588a8 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/warp/event/PreWarpTeleportEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/warp/event/PreWarpTeleportEvent.java
@@ -8,6 +8,7 @@
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
+import org.jspecify.annotations.NonNull;
 import org.jspecify.annotations.Nullable;
 
 /**
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/feature/warp/event/WarpTeleportEvent.java b/eternalcore-api/src/main/java/com/eternalcode/core/feature/warp/event/WarpTeleportEvent.java
index 65fc77cda..df4654c56 100644
--- a/eternalcore-api/src/main/java/com/eternalcode/core/feature/warp/event/WarpTeleportEvent.java
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/feature/warp/event/WarpTeleportEvent.java
@@ -5,6 +5,7 @@
 import org.bukkit.entity.Player;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
+import org.jspecify.annotations.NonNull;
 
 /**
  * Called after teleportation to warp
@@ -38,7 +39,7 @@ public Location getDestination() {
     }
 
     @Override
-    public HandlerList getHandlers() {
+    public @NonNull HandlerList getHandlers() {
         return HANDLER_LIST;
     }
 
diff --git a/eternalcore-api/src/main/java/com/eternalcode/core/package-info.java b/eternalcore-api/src/main/java/com/eternalcode/core/package-info.java
new file mode 100644
index 000000000..4a06f8842
--- /dev/null
+++ b/eternalcore-api/src/main/java/com/eternalcode/core/package-info.java
@@ -0,0 +1,5 @@
+@NullMarked
+package com.eternalcode.core;
+
+import org.jspecify.annotations.NullMarked;
+
diff --git a/eternalcore-core/src/main/java/com/eternalcode/core/feature/chat/ChatServiceImpl.java b/eternalcore-core/src/main/java/com/eternalcode/core/feature/chat/ChatServiceImpl.java
index 3a888f903..ab0d72880 100644
--- a/eternalcore-core/src/main/java/com/eternalcode/core/feature/chat/ChatServiceImpl.java
+++ b/eternalcore-core/src/main/java/com/eternalcode/core/feature/chat/ChatServiceImpl.java
@@ -8,7 +8,6 @@
 import java.time.Instant;
 import java.util.Map;
 import java.util.UUID;
-import org.bukkit.Bukkit;
 import org.bukkit.Server;
 import org.bukkit.entity.Player;
 
diff --git a/eternalcore-core/src/main/java/com/eternalcode/core/feature/home/HomeManager.java b/eternalcore-core/src/main/java/com/eternalcode/core/feature/home/HomeManager.java
index 2909214dd..bbe3223ca 100644
--- a/eternalcore-core/src/main/java/com/eternalcode/core/feature/home/HomeManager.java
+++ b/eternalcore-core/src/main/java/com/eternalcode/core/feature/home/HomeManager.java
@@ -16,6 +16,7 @@
 import java.util.stream.Stream;
 import org.bukkit.Location;
 import org.bukkit.entity.Player;
+import org.jspecify.annotations.Nullable;
 
 @Service
 public class HomeManager implements HomeService {
@@ -46,7 +47,7 @@ private HomeManager(
     }
 
     @Override
-    public Home createHome(UUID playerUniqueId, String name, Location location) {
+    public @Nullable Home createHome(UUID playerUniqueId, String name, Location location) {
         Map<String, Home> homes = this.userHomes.computeIfAbsent(playerUniqueId, k -> new HashMap<>());
 
         Home home = homes.get(name);
diff --git a/eternalcore-core/src/main/java/com/eternalcode/core/feature/spawn/SpawnServiceImpl.java b/eternalcore-core/src/main/java/com/eternalcode/core/feature/spawn/SpawnServiceImpl.java
index d2e0a9916..02936723b 100644
--- a/eternalcore-core/src/main/java/com/eternalcode/core/feature/spawn/SpawnServiceImpl.java
+++ b/eternalcore-core/src/main/java/com/eternalcode/core/feature/spawn/SpawnServiceImpl.java
@@ -4,12 +4,12 @@
 import com.eternalcode.core.configuration.implementation.LocationsConfiguration;
 import com.eternalcode.core.injector.annotations.Inject;
 import com.eternalcode.core.injector.annotations.component.Service;
-import com.eternalcode.commons.bukkit.position.Position;
 import com.eternalcode.commons.bukkit.position.PositionAdapter;
 import io.papermc.lib.PaperLib;
 import org.bukkit.Location;
 import org.bukkit.entity.Player;
 import java.util.logging.Logger;
+import org.jspecify.annotations.Nullable;
 
 @Service
 public class SpawnServiceImpl implements SpawnService {
@@ -45,7 +45,7 @@ public void setSpawnLocation(Location location) {
     }
 
     @Override
-    public Location getSpawnLocation() {
+    public @Nullable Location getSpawnLocation() {
         if (!isSpawnValid()) {
             this.logger.warning(WARNING);
             return null;